When you install the Hema Explorer app (version 3), you can download the included Hema Explorer map for offline use.
The Hema Explorer map is split into sections to make downloading easier. These sections of the Hema Explorer map contain map tiles up to zoom level 12.
If you download all sections of the Hema Explorer map, at that zoom level (12) the whole of Australia takes up around 4.3 gigabytes (Gb) of storage.
If you purchase a subscription, you gain access to the Explorer Map at increased zoom levels up to ZL 16.
With these types of maps, the number of tiles for a zoom level increases around 4 times for each additional zoom level. The data used for each zoom level increases as well, but, due to a number of factors, the space used does not necessarily increase 4 times for each zoom level increase.
- The amount of data used for Zoom Level 13 is a bit over 7Gb
- For Zoom Level 14, it will be a bit over 20Gb
- Zoom Level 15 will be around 43Gb
- Zoom Level 16 will be around 114Gb
At Zoom Level 16, there are around 37,000,000 (yes, that's 37 MILLION!) tiles which make up the Hema Explorer map of Australia.
When you download a specific zoom level, you also download the preceding zoom levels as well (there's no escaping this).
So, you're talking about an approximate download size of just around under 190Gb, with literally millions of individual tile files.
Doing this on a mobile device, likely involving cellular (mobile) connections, and storing this content on internal flash memory or on an SD card (if used) is completely impractical, and not workable.
That's why you cannot download the Hema Explorer map for the whole country at zoom level 16.